Target/iscsi: Add T10-PI indication for iscsi_portal_group

In case an iscsi portal group will be defined as t10_pi enabled,
all connections on top of it will support protected transactions.

T10-PI support may require extra reource allocation and maintenance by
the transport layer, so we don't want to apply them on non-t10_pi network
portals. This is a hook for the iscsi target layer to signal the transport
at connection establishment that this connection will carry protected
transactions.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/iscsi/iscsi_target_core.h

@@ -58,7 +58,8 @@
 #define TA_DEMO_MODE_DISCOVERY		1
 #define TA_DEFAULT_ERL			0
 #define TA_CACHE_CORE_NPS		0
-
+/* T10 protection information disabled by default */
+#define TA_DEFAULT_T10_PI		0
 
 #define ISCSI_IOV_DATA_BUFFER		5
 
@@ -765,6 +766,7 @@ struct iscsi_tpg_attrib {
 	u32			prod_mode_write_protect;
 	u32			demo_mode_discovery;
 	u32			default_erl;
+	u8			t10_pi;
 	struct iscsi_portal_group *tpg;
 };
 
@@ -787,6 +789,7 @@ struct iscsi_np {
 	void			*np_context;
 	struct iscsit_transport *np_transport;
 	struct list_head	np_list;
+	struct iscsi_tpg_np	*tpg_np;
 } ____cacheline_aligned;
 
 struct iscsi_tpg_np {

drivers/target/iscsi/iscsi_target_tpg.c

@@ -225,6 +225,7 @@ static void iscsit_set_default_tpg_attribs(struct iscsi_portal_group *tpg)
 	a->prod_mode_write_protect = TA_PROD_MODE_WRITE_PROTECT;
 	a->demo_mode_discovery = TA_DEMO_MODE_DISCOVERY;
 	a->default_erl = TA_DEFAULT_ERL;
+	a->t10_pi = TA_DEFAULT_T10_PI;
 }
 
 int iscsit_tpg_add_portal_group(struct iscsi_tiqn *tiqn, struct iscsi_portal_group *tpg)
@@ -500,6 +501,7 @@ struct iscsi_tpg_np *iscsit_tpg_add_network_portal(
 	init_completion(&tpg_np->tpg_np_comp);
 	kref_init(&tpg_np->tpg_np_kref);
 	tpg_np->tpg_np		= np;
+	np->tpg_np		= tpg_np;
 	tpg_np->tpg		= tpg;
 
 	spin_lock(&tpg->tpg_np_lock);